Quantitative Trait Loci Mapping of Dark-Induced Senescence in Winter Wheat (Triticum aestivum)

In order to explore the genetics of dark-induced senescence in winter wheat (Triticum aestivum L.), a quantitative trait loci (QTL) analysis was carried out in a doubled haploid population developed from a cross between the varieties Hanxuan 10 (HX) and Lumai 14 (LM). The senescence parameters chlorophyll content (Chl a+b, Chl a, and Chl b), original fluorescence (Fo), maximum fluorescence level (Fm), maximum photochemical efficiency (Fv/Fm), and ratio of variable fluorescence to original fluorescence (Fv/Fo) were evaluated in the second leaf of whole three-leaf seedlings subjected to 7 d of darkness. A total of 43 QTLs were identified that were associated with dark-induced senescence using composite interval mapping. These QTLs were mapped to 20 loci distributed on 11 chromosomes: 1B, 1D, 2A, 2B, 3B, 3D, 5D, 6A, 6B, 7A, and 7B. The phenotypic variation explained by each QTL ranged from 7.5% to 19.4%. Eleven loci coincided with two or more of the analyzed parameters. In addition, 14 loci co-located or were linked with previously reported QTLs regulating flag leaf senescence, tolerance to high light stress, and grain protein content (Gpc), separately.